That's a difficult question, since many of the best Amiga games were ported to (or from) other platforms. Another vote for XTReme Racing. All of the others I am thinking of (Cannon Fodder, Worms, Nebulus, Zool to name a few) were available on other platforms.
Actually, wasn't Worms: The Directors Cut an Amiga only version? If so then that would be a definite favourite Amiga-only game. It was, and still is, the best version of Worms.
I wonder if it would have made any difference to the Amiga's fate if all those classics which were ported to other platforms had been left as Amiga-only titles. It might have brought in more users and funded the platform sufficiently to keep it alive.
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I would like to point out that hearing my PC-owning friends bragging about this great new DOS game they can play, then seeing that it was a conversion of Zool with crap graphics and awful sound made me furious! :lol: They didn't seem to understand that these games had been around for ages on the Amiga, and were much better!
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moto